The present invention is directed to the fields of Prosthodontics, Orthodontics, Maxillofacial Surgery specially in the branch of dentomaxillofacial anomalies where the use of the apparatus is obligatory for the study and analysis of these anomalies.
From the existing equipment, a number of things are known. For example, the National Gnathostat apparatus for the confection of static maxillar models clinical references are taken such as: the E-E-P (ear-eye plane), the R-M-P (raphe-median plane) and the O-P (orbital plane) of Simon. These static patterns are used in the diagnosis of dentobuccal deviation and anomalies of the mentioned planes. The above is noted by J. A. Salzmann, Orthodontics, Practice and Technics, Lippincott Co., 1957, Pgs. 211-216.
Also known is the method of outlining dental-alveole patterns according to the planes and points of the cephalometric analysis using ruler, compass, scissors, knives to measure and cut the patterns in accordance with this analysis. See, Sassouni, Orthodontics in Dental Practice, Mosby Co., St. Louis, 1971, Pgs. 253-259.
The method of outlining the dental-alveole patterns with reference to the points and planes of the cephalometric analysis is made by cutting the base of the model according to the mandibular plane; the base of the upper model is outlined according to the palatal plane; the anterior part of the upper model is delimited by the anterior nasal spine and the anterior part of the lower model is delimited by the pogonio; the posterior borders of both models are outlined according to a perpendicular to the plane of Frankfort. All these cuts are made by measurements and studies of the cephalometric analysis.
The maxillar models made through cephalometric analysis without the assistance of an apparatus is not completely exact since the transcription of measurements and angles of the planes is frequently made by cutting counter-drawings of these planes and angles in cardboard, outlining the dental alveole casts by comparison, and using the teleradiography, the patterns are shaped and scraped to obtain reference of the planes described above. Besides, the patterns obtained are only connected by the dental joint which makes difficult and inexact the measurements for possible corrections.